Carlyle in Talks to Buy J&J's Blood-Testing Unit

Carlyle Group LP is in exclusive talks with Johnson & Johnson to acquire the health-care company's blood-testing unit, which is expected to fetch about $4 billion, according to people familiar with the matter.

The talks could still fall apart, they cautioned. But Washington, D.C.-based Carlyle has emerged from a number of bidders as the most likely to acquire J&J's Ortho Clinical Diagnostics unit.